The present invention relates to an assembly and method for manufacturing a green tyre and/or a green air spring.
It is common practice to arrange tyre components such as various plies for a tyre on a building drum. Various layers of rubber, such as for instance the airtight liner, the sidewalls and the tread are combined with reinforcement plies, such as for instance carcass plies and breaker plies.
For manufacturing a tyre, such as for instance a car tyre or truck tyre, the tyre components, particularly the various layers of unvulcanized rubber, in the form of bands of rubber material are placed on the building drum, and formed further into a green tyre. It is among other things of importance that the tyre component is placed at the correct position on the building drum.
Another method of manufacturing a tyre is to build up the layers of rubber material on the building drum by means of a process that is usually referred to as ‘strip winding’. Such a method and related device are for instance described in EP 1.827.807. The device is provided with an extrusion device that is adapted for extruding a thin strip of unvulcanized rubber, wherein the extruded strip is helically wound around the building drum for thus forming the desired layer of the rubber material. As the desired layer is in fact built up on the building drum by winding a thin strip, the dimensions of the desired layer can easily be adjusted by adjusting the winding process. A drawback of ‘strip winding’ is that particularly the accuracy of the dimensions of the obtained layer by building up by means of winding an extruded strip on a rotating drum is less than in case of arranging a pre-fabricated band of rubber material.